Changes in embryonic development, hatching, and zoeae of snow crab with variation in incubation temperature

Abstract

The effect of incubation temperature on duration of embryonic development and morphology, weight and energetic content of post-hatch zoeae was described for snow crab, Chionoecetes opilio, from the eastern Bering Sea held at -1, 0, 1, 3, and 6° C in the laboratory from collection to hatch. The mean incubation time increased with decreasing temperature by 32% (113 d) between 6 and -1° C. Extrusion success of females at 6° C was lower versus 0 or 3° C, but the duration of hatching did not vary significantly with incubation temperature. A one-year cycle of embryo incubation was observed, indicating that switching from one to two-year duration of embryo incubation may occur early in development. The energy content and individual weights of post-hatch zoeae were not significantly affected by temperature, indicating that longer incubation periods may not have an energetic cost. The rostro-dorsal length of zoeae incubated at 6° C was smaller than those from cooler temperatures. Conversely, the length of the 3rd abdominal somite increased significantly with decreasing temperature, perhaps serving as an indicator of incubation temperature in field collected zoeae. The consequences of varying incubation temperature appear on post-hatch zoeae appear to be limited between -1° and 6° C.